PIC18F6393 Datasheet, PDF (34/58 Pages) Microchip Technology – 64/80-Pin High Performance,

PIC18F6393/6493/8393/8493
The analog reference voltage is software selectable to
either the device’s positive and negative supply voltage
(VDD and VSS), or the voltage level on the RA3/AN3/
VREF+/SEG17 and RA2/AN2/VREF-/SEG16 pins.
The A/D Converter has a unique feature of being able
to operate while the device is in Sleep mode. To oper-
ate in Sleep, the A/D conversion clock must be derived
from the A/D’s internal RC oscillator.
The output of the sample and hold is the input into the
converter, which generates the result via successive
approximation.
A device Reset forces all registers to their Reset state.
This forces the A/D module to be turned off and any
conversion in progress is aborted.
Each port pin associated with the A/D Converter can be
configured as an analog input or a digital I/O. The
ADRESH and ADRESL registers contain the result of
the A/D conversion. When the A/D conversion is com-
plete, the result is loaded into the ADRESH:ADRESL
register pair, the GO/DONE bit (ADCON0<1>) is cleared
and the A/D Interrupt Flag bit, ADIF, is set. The block
diagram of the A/D module is shown in Figure 2-1.
FIGURE 2-1:
A/D BLOCK DIAGRAM
CHS3:CHS0
1011
1010
1001
1000
0111
0110
0101
12-Bit
A/D
Converter
VAIN
(Input Voltage)
0100
0011
0010
VCFG1:VCFG0
Reference
Voltage
VREF+
VREF-
AVDD⁽¹⁾
X0
X1
1X
0X
AVSS⁽¹⁾
Note 1: I/O pins have diode protection to VDD and VSS.
0001
0000
AN11
AN10
AN9
AN8
AN7
AN6
AN5
AN4
AN3
AN2
AN1
AN0
DS39896A-page 32
Preliminary
© 2007 Microchip Technology Inc.